1. Field of the Invention
The present invention relates generally to fish containment systems, tanks, structures, net enclosures, pens and cages or other defined containers, and more particularly to buoyant aquaculture systems, cages, self-contained housings, and floating containment structures for rearing fish, invertebrates, algae, seaweeds, and the like.
2. Discussion of the Related Art
In recent years, the importance of fish in human diets has attained renewed recognition due to dietary research comparing the health benefits, as well as negative health impacts, of fish and other meats. Consumer demand for fish has increased, and commercial farmers have searched for new techniques for producing more fish while minimizing the impact on the environment. Aquaculture, or fish-farming, has gained attention as a viable alternative to commercial harvesting of wild fish populations. Aquaculture is practiced in several different forms, which include land-based aquaculture systems such as open ponds and recirculating tank systems; and open water aquaculture such as net pen/cage systems and floating closed containment systems as described herein. Aquaculture may also increase the availability of seafood and freshwater fish for public food consumption. Aquaculture also reduces the ecological impact of fishing by eliminating the use of nets for harvesting seafood and by reducing the impact of commercial harvesting on wild populations that can produce negative ecological results in a particular marine or freshwater environment.
Net pen/cage aquaculture has been practiced for thousands of years in freshwater lakes and nearshore ocean sites, however over the last 10 years has received tremendous criticism and environmental scrutiny for its highly pollutive effects, and escapism of non-native species into the environment. Further, the pollutive nature of net pen/cage systems has severely limited their applications globally as they cannot be sited/positioned in closed bodies of water such as lakes; areas with low current/tidal exchange; or environmentally sensitive areas. Many commercial farmers, non-governmental and governmental agencies have sought to eliminate the use of net pens/cages and replace them with land and water-based closed containment systems that eliminate pollution and escapement. Aquaculture practices and systems must conform to rapidly expanding environmental legislation in order for the industry to meet global seafood demand.
U.S. Pat. No. 6,539,894, issued to Byrne et al. on Apr. 1, 2003, discloses an aquaculture system particularly designed for the cultivation, containment and growing of various mollusks, and discloses a generally rectangular housing of rigid-molded panels, which include internal openings such that food and mollusks can migrate between chambers. The individual panels constitute interior baffles onto which the mollusks may attach and grow. The '894 patent teaches that the panels are to be constructed of blow-molded plastic, such as polyethylene or similar materials. A foam insert is placed between inner and outer panel sides in a particular embodiment. The closed-cell foam provides the desired buoyancy.
U.S. Pat. No. 5,617,813, issued to Loverich et al. on Apr. 3, 1997, discloses an anchorable and mobile pen system for growing fish, shellfish and the like. The mobile pens are shown in different shapes and utilize a flexible netting form system to enclose the pen between spar buoys. The netting is supported in any desired shape by a supporting ring structure.
U.S. Pat. No. 4,351,269, issued to Rines et al. on Sep. 28, 1982, discloses a training device for various fish species, and is designed to control the congregation and feeding habits of the fish. The focus is to cause the fish to congregate in vertical stacks under light-blocking covers contacting the water, however without defined containers which utilize nets, walls or other barriers to the flow of water. The opaque covers are made from fiberglass or similar materials, and can be arranged in any configuration, including square, rectangular, circular or otherwise. Feed is introduced around the perimeter of the device, or alternatively through centralized tubes.
U.S. Pat. No. 5,762,024 issued to Meilahn on Jun. 9, 1998, describes an aquaculture system having a rigid-walled floating tank that is generally cylindrical with a conical bottom. The '024 patent has a disadvantage in that the tank has a rigid wall that does not articulate and deform in order to absorb the impact of waves and wind. Thus, the '024 invention is more prone to damage by wind and wave action than the articulated, individually moveable tank wall panels of the present invention.
U.S. Pat. No. 4,395,970 issued to Kunkle et al. on Aug. 2, 1982, and U.S. Pat. No. 6,386,146 issued to Knott on May 14, 2002, disclose conventional fish habitats or aquaculture devices utilizing nets, screens, impervious walls and various flotation mechanisms. Many of the references disclose tethering, anchoring and buoyancy systems.
While the above patent references disclose various aquaculture devices and systems, there remains a definite need for an improved fish production system that provides a floating containment tank sectional with flexible membranes spanning between and interconnecting to solid rigid tank wall and floor sections, allowing for articulation and temporary deforming of the tank configuration in response to external forces. The prior art does not disclose, illustrate or suggest many of the components of the instant floating closed containment system, including the generally cylindrical tank enclosure with articulating, individually moveable tank wall and floor sections and a conical-shaped bottom, to promote waste collection and removal.